Electric-contact protector



(No Model.)

B. VARLEY, Jr. ELECTRIC CONTACT PROTECTOR.

No. 473,717. Patented Apr. 26, 1892.

UNITE STATES PATENT OFFICE.

RICHARD VARLEY, JR, OF ENGLElVOOD, NEWV JERSEY.

ELECTRIC-CONTACT PROTECTOR.

SPECIFICATION forming part of Letters Patent No. 473,717, dated April26, 1892. Application filed July 7, 1891. Serial No. 898,667. (Nomodel.)

To all whom it may concern.-

Be it known that I, RICHARD VARLEY, J12, a citizen of the United States,residingin Englewood,in the county of Bergen and State of New Jersey,have invented an Improvement in Electric-Contact Protectors, of whichthe following is a specification.

In Letters Patent No. 449,302, granted to me March 31, 1891, an elasticshield is placed over the electric contacts in such a manner as toexclude air and dust from such contacts, and thereby lessen the risk ofthe same becoming inoperative by the presence of oxide or of foreignsubstances. In devices made under this patent difficulty has beenexperiencedin putting the parts together with sufficient facility andrapidity not to interfere with the cost of the electric alarm-bell orother structure, to the contact-points of Which the improvement wasapplied.

My present invention is an improvement upon the aforesaid device, andrelates to the combination, with one contact-point passing through theelastic shield, of a second contact over which a rubber band or septumis drawn, the second contact being in a recess, so that there is roomfor the head of the other electrode in the recess; but the rubber bandor septum remains air-tight, or nearly so, around the contacts.

In the drawings, Figure l is an elevation of one of the electriccontacts and a section of the rubber shield and of the other contact.Fig. 2 is a face view of one of the contacts with the rubber shieldpartially removed and with the other contact in section at its neck, andFig. 3 is a plan view of the plate-contact.

It is to be understood that this improvement is available for theexclusion of atmosphere from the electric contacts upon fingerkeys andmany other electric instruments; but it is especially available upon thebackstop in electric alarm-bells, and these contacts are usually madebetween a plate or spring A and an adjusting-screw B, the latter passingthrough any suitable standard 0, and the spring is generally upon orreceives its motion from the armature of the bell.

The screw B is of any desired size; but there is a neck 2 turned orformed in the screw near the end thereof, and the rubber shield or septnn1 D is perforated, so that the small button-shaped end of the screw Bcan be pressed through the elastic shield or septum, and such elasticmaterial will contract around the neck 2. i

The plate or spring A is recessed for the reception of the electrode,which is preferably in the form of a small platina plate introduced intosuch recess 3 and soldered to place, and it is advantageous to have thesurface of the plate A convex or provided with ribs, in order that thesurface of the rubber shield or septum, which is in contact with suchplate or spring A, may set closely against such convex surface orprojecting ribs and remain airtight.

The elastic shield or septum is to be drawn sufiiciently tight againstthe surface of the plate or spring A to be air-tight against the same,and any suitable device may be made use of in holding this rubber septumfirmly against the surface of the plate or spring A. I prefer and findit convenient and cheap to make this shield or septum in the form of athin fiat rubber band of sufficient Width, so that such band may passaround the end of the plate or spring A, the elastic material beingstretched sufficiently as it is applied to the plate or spring to causethe said elastic shield to contract firmly against the face of the plateor spring. Hence in putting the parts together it is only necessary todraw back the screw B sufficiently for applying the elastic shield orseptum around the end of the plate or spring A, with the small holetherein opposite the platina end of the screw B, and by a small fork orsimilar instrument between the septum and the plate or spring A therubber can be forced over the button end of the adjusting-screw B, andthen it will contract and become substantially air-tight against theface of the plate or spring A when such tool or fork has been withdrawnfrom behind the rubber.

It is advantageous to make the recess 3 sn fficiently deep for thereception of the button. head or end of the screw B, in order that therubber septum may not be under strain in its normal position. Hence theelectrodes can be separated or brought into contact without the rubberseptum exerting any obstructive force to the movement of the parts.

The button-head is generally preferably at the end of the one electrode;but the elastic septum contracts with suffieient force to prevent theseparation of the parts under the small movement usual in electricinstruments, even when the head is dispensed with.

I am aware that a ball of rubber has been used having Within it separateconductorplates, to Whichare affixed the conductors, and the circuit hasbeen closed by a movable plate, also within the ball. Hence my inventiondoes not relate, broadly, to the circuitclosing devices protected byarubberenvelope.

I claim as my invention 1. Two electrodes, one of which is recessed inline with the other electrode, in combination with an elastic septumthrough Which one electrode passes and Which septum sets tightly againstthe raised surface of the other electrode, substantially as specified.

2. The combination, with an elastic septum in the form of a band, of anelectrode made as a plate introduced into the elastic band and theopposite electrode having a neck, the

elastic septum surrounding the neck and lying close upon the surface ofthe electrodeplate, substantially as set forth.

3. An electrode plate or spring having a recess and a plate of platinaor similar metal secured in the base of the recess,in combination withan elastic septum secured to the face of the plate, and anadjusting-screw having a neck near the end and passed through theelastic septum into the cavity of the plate, substantially as set forth.

4. An electrode formed of a plate of metal recessed and having a convexor projecting surface around the recess, in combination With an elasticband passing around such plate and drawn tightly upon the convex surfaceto form an air-tight septum and perforated in line with the recess, andan electrode having a neck and a head Within the recess and the elasticmaterial surrounding the neck, substantially as set forth.

Signed by me this 1st day of July, 1891.

R. VARLEY, JR. Witnesses:

GEO. T. PINCKNEY, WILLIAM G. MOTT.

